Here is the full list of all 19 Secrets of Rætikon achievements.
Hatch a bird
Lift a lynx in the air by its tail
Dive the deepest well
Find all hidden rune orbs
Get a daw to fight a buzzard
Feed the daw with prey
Get a female rabbit to give birth to 8 babies
Get a buzzard to hit a lynx
Carry a total of 130 slivers
Hurt a buzzard by letting it dash into a solid
Bring an animal from one area to another
Hatch a buzzard and let it kill a lynx
Throw and Catch rabbit in mid air
Hit an animal with a thistle
Avoid the unavoidable
Hurt an animal with a stone you dropped
Don't hurt anything
Never get critical health
Never get hurt